#
# gPrime - A web-based genealogy program
#
# Copyright (C) 2000-2007  Donald N. Allingham
# Copyright (C) 2010       Michiel D. Nauta
# Copyright (C) 2010       Jakim Friant
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
#

"""
Provide merge capabilities for persons.
"""

#-------------------------------------------------------------------------
#
# Gprime modules
#
#-------------------------------------------------------------------------
from ..db import DbTxn
from ..const import LOCALE as glocale
_ = glocale.translation.sgettext
from ..errors import MergeError

#-------------------------------------------------------------------------
#
# MergePersonQuery
#
#-------------------------------------------------------------------------
class MergePersonQuery:
    """
    Create database query to merge two persons.
    """
    def __init__(self, database, phoenix, titanic):
        self.database = database
        self.phoenix = phoenix
        self.titanic = titanic
        if self.check_for_spouse(self.phoenix, self.titanic):
            raise MergeError(_("Spouses cannot be merged. To merge these "
                "people, you must first break the relationship between them."))
        if self.check_for_child(self.phoenix, self.titanic):
            raise MergeError(_("A parent and child cannot be merged. To merge "
                "these people, you must first break the relationship between "
                "them."))

    def check_for_spouse(self, person1, person2):
        """Return if person1 and person2 are spouses of eachother."""
        fs1 = set(person1.get_family_handle_list())
        fs2 = set(person2.get_family_handle_list())
        return len(fs1.intersection(fs2)) != 0

    def check_for_child(self, person1, person2):
        """Return if person1 and person2 have a child-parent relationship."""
        fs1 = set(person1.get_family_handle_list())
        fp1 = set(person1.get_parent_family_handle_list())
        fs2 = set(person2.get_family_handle_list())
        fp2 = set(person2.get_parent_family_handle_list())
        return len(fs1.intersection(fp2)) != 0 or len(fs2.intersection(fp1))

    def merge_families(self, main_family_handle, family, trans):
        """
        Merge content of family into the family with handle main_family_handle.
        """
        new_handle = self.phoenix.get_handle() if self.phoenix else None
        old_handle = self.titanic.get_handle() if self.titanic else None
        family_handle = family.get_handle()
        main_family = self.database.get_family_from_handle(main_family_handle)
        main_family.merge(family)
        for childref in family.get_child_ref_list():
            child = self.database.get_person_from_handle(
                    childref.get_reference_handle())
            if main_family_handle in child.parent_family_list:
                child.remove_handle_references('Family', [family_handle])
            else:
                child.replace_handle_reference('Family', family_handle,
                    main_family_handle)
            self.database.commit_person(child, trans)
        if self.phoenix:
            self.phoenix.remove_family_handle(family_handle)
            self.database.commit_person(self.phoenix, trans)
        family_father_handle = family.get_father_handle()
        spouse_handle = family.get_mother_handle() if \
                new_handle == family_father_handle else family_father_handle
        spouse = self.database.get_person_from_handle(spouse_handle)
        if spouse:
            spouse.remove_family_handle(family_handle)
            self.database.commit_person(spouse, trans)
        # replace the family in lds ordinances
        for (dummy, person_handle) in self.database.find_backlink_handles(
                family_handle, ['Person']):
            if person_handle == old_handle:
                continue
            person = self.database.get_person_from_handle(person_handle)
            person.replace_handle_reference('Family', family_handle,
                                            main_family_handle)
            self.database.commit_person(person, trans)
        self.database.remove_family(family_handle, trans)
        self.database.commit_family(main_family, trans)

    def execute(self, family_merger=True, trans=None):
        """
        Merges two persons into a single person.
        """
        if trans is None:
            with DbTxn(_('Merge Person'), self.database) as trans:
                self.__execute(family_merger, trans)
        else:
            self.__execute(family_merger, trans)

    def __execute(self, family_merger, trans):
        """
        Merges two persons into a single person; trans is compulsory.
        """
        new_handle = self.phoenix.get_handle()
        old_handle = self.titanic.get_handle()

        self.phoenix.merge(self.titanic)
        self.database.commit_person(self.phoenix, trans)

        for (dummy, person_handle) in self.database.find_backlink_handles(
                old_handle, ['Person']):
            person = self.database.get_person_from_handle(person_handle)
            assert person.has_handle_reference('Person', old_handle)
            person.replace_handle_reference('Person', old_handle, new_handle)
            if person_handle != old_handle:
                self.database.commit_person(person, trans)

        for family_handle in self.phoenix.get_parent_family_handle_list():
            family = self.database.get_family_from_handle(family_handle)
            if family.has_handle_reference('Person', old_handle):
                family.replace_handle_reference('Person', old_handle,new_handle)
                self.database.commit_family(family, trans)

        family_merge_guard = False
        parent_list = []
        parent_list_orig = []
        family_handle_list = self.phoenix.get_family_handle_list()[:]
        for family_handle in family_handle_list:
            family = self.database.get_family_from_handle(family_handle)
            parents = (family.get_father_handle(), family.get_mother_handle())
            parent_list_orig.append(parents)
            if family.has_handle_reference('Person', old_handle):
                if family_merger and parent_list_orig.count(parents) > 1:
                    raise MergeError(_("A person with multiple relations with "
                        "the same spouse is about to be merged. This is beyond "
                        "the capabilities of the merge routine. The merge is "
                        "aborted."))
                family.replace_handle_reference('Person', old_handle,new_handle)
                parents = (family.get_father_handle(),
                           family.get_mother_handle())
                # prune means merging families in this case.
                if family_merger and parents in parent_list:
                    # also merge when father_handle or mother_handle == None!
                    if family_merge_guard:
                        raise MergeError(_("Multiple families get merged. "
                            "This is unusual, the merge is aborted."))
                    idx = parent_list.index(parents)
                    main_family_handle = family_handle_list[idx]
                    self.merge_families(main_family_handle, family, trans)
                    family_merge_guard = True
                    continue
                self.database.commit_family(family, trans)
            parent_list.append(parents)

        self.database.remove_person(old_handle, trans)
